citadel/modules/smtp/serv_smtpclient.c

   1 /*
   2  * Transmit outbound SMTP mail to the big wide world of the Internet
   3  *
   4  * This is the new, exciting, clever version that makes libcurl do all the work  :)
   5  *
   6  * Copyright (c) 1997-2017 by the citadel.org team
   7  *
   8  * This program is open source software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as published
  10  * by the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <stdio.h>
  22 #include <sysconfig.h>
  23
  24 #if TIME_WITH_SYS_TIME
  25 # include <sys/time.h>
  26 # include <time.h>
  27 #else
  28 # if HAVE_SYS_TIME_H
  29 #  include <sys/time.h>
  30 # else
  31 #  include <time.h>
  32 # endif
  33 #endif
  34
  35 #include <ctype.h>
  36 #include <string.h>
  37 #include <errno.h>
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <libcitadel.h>
  41 #include <curl/curl.h>
  42 #include "citadel.h"
  43 #include "server.h"
  44 #include "citserver.h"
  45 #include "support.h"
  46 #include "config.h"
  47 #include "ctdl_module.h"
  48 #include "clientsocket.h"
  49 #include "msgbase.h"
  50 #include "domain.h"
  51 #include "internet_addressing.h"
  52 #include "citadel_dirs.h"
  53 #include "modules/smtp/smtp_util.h"
  54
  55 struct smtpmsgsrc {             // Data passed in and out of libcurl for message upload
  56         StrBuf *TheMessage;
  57         int bytes_total;
  58         int bytes_sent;
  59 };
  60
  61 struct CitContext smtp_client_CC;
  62 static int doing_smtpclient = 0;
  63 long *smtpq = NULL;             // array of msgnums containing queue instructions
  64 int smtpq_count = 0;            // number of queue messages in smtpq
  65 int smtpq_alloc = 0;            // current allocation size for smtpq
  66
  67
  68 /*
  69  * Initialize the SMTP outbound queue
  70  */
  71 void smtp_init_spoolout(void) {
  72         struct ctdlroom qrbuf;
  73
  74         /*
  75          * Create the room.  This will silently fail if the room already
  76          * exists, and that's perfectly ok, because we want it to exist.
  77          */
  78         CtdlCreateRoom(SMTP_SPOOLOUT_ROOM, 3, "", 0, 1, 0, VIEW_QUEUE);
  79
  80         /*
  81          * Make sure it's set to be a "system room" so it doesn't show up
  82          * in the <K>nown rooms list for administrators.
  83          */
  84         if (CtdlGetRoomLock(&qrbuf, SMTP_SPOOLOUT_ROOM) == 0) {
  85                 qrbuf.QRflags2 |= QR2_SYSTEM;
  86                 CtdlPutRoomLock(&qrbuf);
  87         }
  88 }
  89
  90
  91 /* For internet mail, generate delivery instructions.
  92  * Yes, this is recursive.  Deal with it.  Infinite recursion does
  93  * not happen because the delivery instructions message does not
  94  * contain a recipient.
  95  */
  96 int smtp_aftersave(struct CtdlMessage *msg, recptypes *recps)
  97 {
  98         if ((recps != NULL) && (recps->num_internet > 0)) {
  99                 struct CtdlMessage *imsg = NULL;
 100                 char recipient[SIZ];
 101                 StrBuf *SpoolMsg = NewStrBuf();
 102                 long nTokens;
 103                 int i;
 104
 105                 syslog(LOG_DEBUG, "smtpclient: generating delivery instructions");
 106
 107                 StrBufPrintf(SpoolMsg,
 108                              "Content-type: "SPOOLMIME"\n"
 109                              "\n"
 110                              "msgid|%s\n"
 111                              "submitted|%ld\n"
 112                              "bounceto|%s\n",
 113                              msg->cm_fields[eVltMsgNum],
 114                              (long)time(NULL),
 115                              recps->bounce_to);
 116
 117                 if (recps->envelope_from != NULL) {
 118                         StrBufAppendBufPlain(SpoolMsg, HKEY("envelope_from|"), 0);
 119                         StrBufAppendBufPlain(SpoolMsg, recps->envelope_from, -1, 0);
 120                         StrBufAppendBufPlain(SpoolMsg, HKEY("\n"), 0);
 121                 }
 122                 if (recps->sending_room != NULL) {
 123                         StrBufAppendBufPlain(SpoolMsg, HKEY("source_room|"), 0);
 124                         StrBufAppendBufPlain(SpoolMsg, recps->sending_room, -1, 0);
 125                         StrBufAppendBufPlain(SpoolMsg, HKEY("\n"), 0);
 126                 }
 127
 128                 nTokens = num_tokens(recps->recp_internet, '|');
 129                 for (i = 0; i < nTokens; i++) {
 130                         long len;
 131                         len = extract_token(recipient, recps->recp_internet, i, '|', sizeof recipient);
 132                         if (len > 0) {
 133                                 StrBufAppendBufPlain(SpoolMsg, HKEY("remote|"), 0);
 134                                 StrBufAppendBufPlain(SpoolMsg, recipient, len, 0);
 135                                 StrBufAppendBufPlain(SpoolMsg, HKEY("|0||\n"), 0);
 136                         }
 137                 }
 138
 139                 imsg = malloc(sizeof(struct CtdlMessage));
 140                 memset(imsg, 0, sizeof(struct CtdlMessage));
 141                 imsg->cm_magic = CTDLMESSAGE_MAGIC;
 142                 imsg->cm_anon_type = MES_NORMAL;
 143                 imsg->cm_format_type = FMT_RFC822;
 144                 CM_SetField(imsg, eMsgSubject, HKEY("QMSG"));
 145                 CM_SetField(imsg, eAuthor, HKEY("Citadel"));
 146                 CM_SetField(imsg, eJournal, HKEY("do not journal"));
 147                 CM_SetAsFieldSB(imsg, eMesageText, &SpoolMsg);
 148                 CtdlSubmitMsg(imsg, NULL, SMTP_SPOOLOUT_ROOM, QP_EADDR);
 149                 CM_Free(imsg);
 150         }
 151         return 0;
 152 }
 153
 154
 155 /*
 156  * Callback for smtp_attempt_delivery() to supply libcurl with upload data.
 157  */
 158 static size_t upload_source(void *ptr, size_t size, size_t nmemb, void *userp)
 159 {
 160         struct smtpmsgsrc *s = (struct smtpmsgsrc *) userp;
 161         int sendbytes = 0;
 162         const char *send_this = NULL;
 163
 164         sendbytes = (size * nmemb);
 165
 166         if (s->bytes_sent >= s->bytes_total) {
 167                 return(0);                                      // we are donez0r
 168         }
 169
 170         if (sendbytes > (s->bytes_total - s->bytes_sent)) {
 171                 sendbytes = s->bytes_total - s->bytes_sent;     // can't send more than we have
 172         }
 173
 174         send_this = ChrPtr(s->TheMessage);
 175         send_this += s->bytes_sent;                             // start where we last left off
 176
 177         memcpy(ptr, send_this, sendbytes);
 178         s->bytes_sent += sendbytes;
 179         return(sendbytes);                                      // return the number of bytes _actually_ copied
 180 }
 181
 182
 183 /*
 184  * Attempt a delivery to one recipient.
 185  * Returns a three-digit SMTP status code.
 186  */
 187 int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from)
 188 {
 189         struct smtpmsgsrc s;
 190         char *fromaddr = NULL;
 191         CURL *curl;
 192         CURLcode res = CURLE_OK;
 193         struct curl_slist *recipients = NULL;
 194         long response_code = 421;
 195         int num_mx = 0;
 196         char mxes[SIZ];
 197         char user[1024];
 198         char node[1024];
 199         char name[1024];
 200         char try_this_mx[256];
 201         char smtp_url[512];
 202         int i;
 203
 204         syslog(LOG_DEBUG, "smtpclient: smtp_attempt_delivery(%ld, %s)", msgid, recp);
 205
 206         process_rfc822_addr(recp, user, node, name);            // split recipient address into username, hostname, displayname
 207         num_mx = getmx(mxes, node);
 208         if (num_mx < 1) {
 209                 return(421);
 210         }
 211
 212         CC->redirect_buffer = NewStrBufPlain(NULL, SIZ);
 213         CtdlOutputMsg(msgid, MT_RFC822, HEADERS_ALL, 0, 1, NULL, 0, NULL, &fromaddr, NULL);
 214         s.TheMessage = CC->redirect_buffer;
 215         s.bytes_total =  StrLength(CC->redirect_buffer);
 216         s.bytes_sent = 0;
 217         CC->redirect_buffer = NULL;
 218         response_code = 421;
 219
 220         for (i=0; ((i<num_mx)&&((response_code/100)==4)); ++i) {                                // keep trying MXes until one works or we run out
 221                 response_code = 421;                                                            // default 421 makes non-protocol errors transient
 222                 s.bytes_sent = 0;                                                               // rewind our buffer in case we try multiple MXes
 223
 224                 curl = curl_easy_init();
 225                 if (curl) {
 226
 227                         if (!IsEmptyStr(envelope_from)) {
 228                                 curl_easy_setopt(curl, CURLOPT_MAIL_FROM, envelope_from);
 229                         }
 230                         else {
 231                                 curl_easy_setopt(curl, CURLOPT_MAIL_FROM, fromaddr);
 232                         }
 233
 234                         recipients = curl_slist_append(recipients, recp);
 235                         curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
 236                         curl_easy_setopt(curl, CURLOPT_READFUNCTION, upload_source);
 237                         curl_easy_setopt(curl, CURLOPT_READDATA, &s);
 238                         curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);                                              // tell libcurl we are uploading
 239                         curl_easy_setopt(curl, CURLOPT_TIMEOUT, 20L);                                           // Time out after 20 seconds
 240                         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
 241                         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
 242                         // curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_error_buffer);
 243
 244                         // Construct an SMTP URL in the form of:
 245                         //      smtp[s]://target_host/source_host
 246                         // This looks weird but libcurl uses that last part to set our name for EHLO or HELO.
 247                         // We check for "smtp://" and "smtps://" because the admin may have put those prefixes in a smart-host entry.
 248                         // If there is no prefix we add "smtp://"
 249                         extract_token(try_this_mx, mxes, i, '|', (sizeof try_this_mx - 7));
 250                         snprintf(smtp_url, sizeof smtp_url,
 251                                 "%s%s/%s",
 252                                 (((!strncasecmp(try_this_mx, HKEY("smtp://"))) || (!strncasecmp(try_this_mx, HKEY("smtps://")))) ? "" : "smtp://"),
 253                                 try_this_mx,
 254                                 CtdlGetConfigStr("c_fqdn")
 255                         );
 256                         curl_easy_setopt(curl, CURLOPT_URL, smtp_url);
 257                         syslog(LOG_DEBUG, "smtpclient: trying %s", smtp_url);                           // send the message
 258                         res = curl_easy_perform(curl);
 259                         curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
 260                         syslog(LOG_DEBUG, "smtpclient: libcurl returned %d (%s) , SMTP response %ld",
 261                                 res, curl_easy_strerror(res), response_code
 262                         );
 263
 264                         if ((res != CURLE_OK) && (response_code == 0)) {                                // check for errors
 265                                 response_code = 421;
 266                         }
 267
 268                         curl_slist_free_all(recipients);
 269                         recipients = NULL;                                                              // this gets reused; avoid double-free
 270                         curl_easy_cleanup(curl);
 271                         curl = NULL;                                                                    // this gets reused; avoid double-free
 272                 }
 273         }
 274
 275         FreeStrBuf(&s.TheMessage);
 276         if (fromaddr) free(fromaddr);
 277         return((int)response_code);
 278 }
 279
 280
 281 /*
 282  * Process one outbound message.
 283  */
 284 void smtp_process_one_msg(long qmsgnum)
 285 {
 286         struct CtdlMessage *msg = NULL;
 287         char *instr = NULL;
 288         int i;
 289         int num_success = 0;
 290         int num_fail = 0;
 291         int num_delayed = 0;
 292         long deletes[2];
 293         int delete_this_queue = 0;
 294
 295         msg = CtdlFetchMessage(qmsgnum, 1, 1);
 296         if (msg == NULL) {
 297                 syslog(LOG_WARNING, "smtpclient: %ld does not exist", qmsgnum);
 298                 return;
 299         }
 300
 301         instr = msg->cm_fields[eMesageText];
 302         msg->cm_fields[eMesageText] = NULL;
 303         CM_Free(msg);
 304
 305         // if the queue message has any CRLF's convert them to LF's
 306         char *crlf = NULL;
 307         while (crlf = strstr(instr, "\r\n"), crlf != NULL) {
 308                 strcpy(crlf, crlf+1);
 309         }
 310
 311         // Strip out the headers and we are now left with just the instructions.
 312         char *soi = strstr(instr, "\n\n");
 313         if (soi) {
 314                 strcpy(instr, soi+2);
 315         }
 316
 317         long msgid = 0;
 318         time_t submitted = time(NULL);
 319         time_t attempted = 0;
 320         char *bounceto = NULL;
 321         char *envelope_from = NULL;
 322
 323         char cfgline[SIZ];
 324         for (i=0; i<num_tokens(instr, '\n'); ++i) {
 325                 extract_token(cfgline, instr, i, '\n', sizeof cfgline);
 326                 if (!strncasecmp(cfgline, HKEY("msgid|")))              msgid = atol(&cfgline[6]);
 327                 if (!strncasecmp(cfgline, HKEY("submitted|")))          submitted = atol(&cfgline[10]);
 328                 if (!strncasecmp(cfgline, HKEY("attempted|")))          attempted = atol(&cfgline[10]);
 329                 if (!strncasecmp(cfgline, HKEY("bounceto|")))           bounceto = strdup(&cfgline[9]);
 330                 if (!strncasecmp(cfgline, HKEY("envelope_from|")))      envelope_from = strdup(&cfgline[14]);
 331         }
 332
 333         int should_try_now = 0;
 334         if (attempted < submitted) {                            // If no attempts have been made yet, try now
 335                 should_try_now = 1;
 336         }
 337         else if ((attempted - submitted) <= 14400) {
 338                 if ((time(NULL) - attempted) > 1800) {          // First four hours, retry every 30 minutes
 339                         should_try_now = 1;
 340                 }
 341         }
 342         else {
 343                 if ((time(NULL) - attempted) > 14400) {         // After that, retry once every 4 hours
 344                         should_try_now = 1;
 345                 }
 346         }
 347
 348         if (should_try_now) {
 349                 syslog(LOG_DEBUG, "smtpclient: %ld attempting delivery now", qmsgnum);
 350                 StrBuf *NewInstr = NewStrBuf();
 351                 StrBufAppendPrintf(NewInstr, "Content-type: "SPOOLMIME"\n\n");
 352                 StrBufAppendPrintf(NewInstr, "msgid|%ld\n", msgid);
 353                 StrBufAppendPrintf(NewInstr, "submitted|%ld\n", submitted);
 354                 if (bounceto) StrBufAppendPrintf(NewInstr, "bounceto|%s\n", bounceto);
 355                 if (envelope_from) StrBufAppendPrintf(NewInstr, "envelope_from|%s\n", envelope_from);
 356
 357                 for (i=0; i<num_tokens(instr, '\n'); ++i) {
 358                         extract_token(cfgline, instr, i, '\n', sizeof cfgline);
 359                         if (!strncasecmp(cfgline, HKEY("remote|"))) {
 360                                 char recp[SIZ];
 361                                 int previous_result = extract_int(cfgline, 2);
 362                                 if ((previous_result == 0) || (previous_result == 4)) {
 363                                         int new_result = 421;
 364                                         extract_token(recp, cfgline, 1, '|', sizeof recp);
 365                                         new_result = smtp_attempt_delivery(msgid, recp, envelope_from);
 366                                         syslog(LOG_DEBUG, "smtpclient: recp: <%s> , result: %d (%s)", recp, new_result, smtpstatus(new_result));
 367                                         if ((new_result / 100) == 2) {
 368                                                 ++num_success;
 369                                         }
 370                                         else {
 371                                                 if ((new_result / 100) == 5) {
 372                                                         ++num_fail;
 373                                                 }
 374                                                 else {
 375                                                         ++num_delayed;
 376                                                 }
 377                                                 StrBufAppendPrintf(NewInstr, "remote|%s|%ld|%ld (%s)\n",
 378                                                         recp, (new_result / 100) , new_result, smtpstatus(new_result)
 379                                                 );
 380                                         }
 381                                 }
 382                         }
 383                 }
 384
 385                 StrBufAppendPrintf(NewInstr, "attempted|%ld\n", time(NULL));
 386
 387                 // All deliveries have now been attempted.  Now determine the disposition of this queue entry.
 388
 389                 time_t age = time(NULL) - submitted;
 390                 syslog(LOG_DEBUG, "smtpclient: submission age: %ldd%ldh%ldm%lds", (age/86400) , ((age%86400)/3600) , ((age%3600)/60) , (age%60));
 391                 syslog(LOG_DEBUG, "smtpclient: num_success=%d , num_fail=%d , num_delayed=%d", num_success, num_fail, num_delayed);
 392
 393                 // If there are permanent fails on this attempt, deliver a bounce to the user.
 394                 // The 5XX fails will be recorded in the rewritten queue, but they will be removed before the next attempt.
 395                 if (num_fail > 0) {
 396                         smtp_do_bounce(ChrPtr(NewInstr), SDB_BOUNCE_FATALS);
 397                 }
 398
 399                 // If all deliveries have either succeeded or failed, we are finished with this queue entry.
 400                 //
 401                 if (num_delayed == 0) {
 402                         delete_this_queue = 1;
 403                 }
 404
 405                 // If it's been more than five days, give up and tell the sender we #failed
 406                 //
 407                 else if ((time(NULL) - submitted) > SMTP_DELIVER_FAIL) {
 408                         smtp_do_bounce(ChrPtr(NewInstr), SDB_BOUNCE_ALL);
 409                         delete_this_queue = 1;
 410                 }
 411
 412                 // If it's been more than four hours but less than five days, warn the sender that I've Been Delayed
 413                 //
 414                 else if ( ((attempted - submitted) < SMTP_DELIVER_WARN) && ((time(NULL) - submitted) >= SMTP_DELIVER_WARN) ) {
 415                         smtp_do_bounce(ChrPtr(NewInstr), SDB_WARN);
 416                 }
 417
 418                 if (delete_this_queue) {
 419                         syslog(LOG_DEBUG, "smtpclient: %ld deleting", qmsgnum);
 420                         deletes[0] = qmsgnum;
 421                         deletes[1] = msgid;
 422                         CtdlDeleteMessages(SMTP_SPOOLOUT_ROOM, deletes, 2, "");
 423                         FreeStrBuf(&NewInstr);                                          // We have to free NewInstr here, no longer needed
 424                 }
 425                 else {
 426                         // replace the old queue entry with the new one
 427                         syslog(LOG_DEBUG, "smtpclient: %ld rewriting", qmsgnum);
 428                         msg = convert_internet_message_buf(&NewInstr);                  // This function will free NewInstr for us
 429                         CtdlSubmitMsg(msg, NULL, SMTP_SPOOLOUT_ROOM, 0);
 430                         CM_Free(msg);
 431                         CtdlDeleteMessages(SMTP_SPOOLOUT_ROOM, &qmsgnum, 1, "");
 432                 }
 433         }
 434         else {
 435                 syslog(LOG_DEBUG, "smtpclient: %ld retry time not reached", qmsgnum);
 436         }
 437
 438         if (bounceto != NULL)           free(bounceto);
 439         if (envelope_from != NULL)      free(envelope_from);
 440         free(instr);
 441 }
 442
 443
 444 /*
 445  * Callback for smtp_do_queue()
 446  */
 447 void smtp_add_msg(long msgnum, void *userdata) {
 448
 449         if (smtpq == NULL) {
 450                 smtpq_count = 0;
 451                 smtpq_alloc = 100;
 452                 smtpq = malloc(smtpq_alloc * sizeof(long));
 453         }
 454
 455         if (smtpq_alloc >= smtpq_count) {
 456                 smtpq_alloc += 100;
 457                 smtpq = realloc(smtpq, (smtpq_alloc * sizeof(long)));
 458         }
 459
 460         smtpq[smtpq_count++] = msgnum;
 461 }
 462
 463
 464 /*
 465  * Run through the queue sending out messages.
 466  */
 467 void smtp_do_queue(void) {
 468         int i = 0;
 469
 470         /*
 471          * This is a simple concurrency check to make sure only one smtpclient
 472          * run is done at a time.  We could do this with a mutex, but since we
 473          * don't really require extremely fine granularity here, we'll do it
 474          * with a static variable instead.
 475          */
 476         if (doing_smtpclient) return;
 477         doing_smtpclient = 1;
 478
 479         syslog(LOG_DEBUG, "smtpclient: start queue run");
 480         pthread_setspecific(MyConKey, (void *)&smtp_client_CC);
 481
 482         if (CtdlGetRoom(&CC->room, SMTP_SPOOLOUT_ROOM) != 0) {
 483                 syslog(LOG_WARNING, "Cannot find room <%s>", SMTP_SPOOLOUT_ROOM);
 484                 doing_smtpclient = 0;
 485                 return;
 486         }
 487
 488         // Put the queue in memory so we can close the db cursor
 489         CtdlForEachMessage(MSGS_ALL, 0L, NULL, SPOOLMIME, NULL, smtp_add_msg, NULL);
 490
 491         // We are ready to run through the queue now.
 492         for (i=0; i<smtpq_count; ++i) {
 493                 smtp_process_one_msg(smtpq[i]);
 494         }
 495
 496         smtpq_count = 0;                // don't free it, we will use this memory on the next run
 497         doing_smtpclient = 0;
 498         syslog(LOG_DEBUG, "smtpclient: end queue run");
 499 }
 500
 501
 502 /*
 503  * Module entry point
 504  */
 505 CTDL_MODULE_INIT(smtpclient)
 506 {
 507         if (!threading)
 508         {
 509                 CtdlFillSystemContext(&smtp_client_CC, "SMTP_Send");
 510                 CtdlRegisterMessageHook(smtp_aftersave, EVT_AFTERSAVE);
 511                 CtdlRegisterSessionHook(smtp_do_queue, EVT_TIMER, PRIO_AGGR + 50);
 512                 smtp_init_spoolout();
 513         }
 514
 515         /* return our module id for the log */
 516         return "smtpclient";
 517 }